Multi-zone pressure control carrier

Abstract

A multi-zoned carrier for a chemical-mechanical planarization (CMP) polishing device includes a center cell, a middle cell, and an outer cell. Each of the cells are in fluid communication with each other through multiple conduits equipped with flow restrictors. The combination of cells and conduits allows more uniformity and planarity to be achieved during the chemical-mechanical planarization (CMP) polishing process.

I claim:  
     
       1. A carrier assembly for use in a chemical mechanical polishing apparatus, the assembly comprising: 
       (a) a first cell comprising a first flexible outer membrane;  
       (b) an adjacent second cell comprising a second flexible outer membrane, the second cell in fluid communication with the first cell; and  
       (c) a third cell adjacent the second cell comprising a third flexible outer membrane, the third cell in fluid communication with the first and second cells, a lower surface of the third cell substantially coplanar with lower surfaces of the first and second cells.  
     
     
       2. The carrier of  claim 1 , further comprising: 
       (a) a first conduit extending between the first and the second cell, the first conduit comprising a flow restrictor; and  
       (b) a second conduit extending between the second and the third cell, the second conduit comprising a flow restrictor.  
     
     
       3. The flow restrictor of  claim 2 , wherein the flow restrictor is a tunable orifice. 
     
     
       4. The carrier of  claim 1 , wherein the first cell comprises a substantially cylindrical shape. 
     
     
       5. The carrier of  claim 1 , wherein the second and third cells comprise annular concentric tubes, with a common center with the first cell. 
     
     
       6. A carrier assembly for use in a chemical mechanical polishing apparatus, the assembly comprising: 
       (a) a first cell comprising a first bladder, having a substantially cylindrical shape;  
       (b) a second cell adjacent to and at least partially surrounding the first cell, the second cell comprising a second bladder, the second bladder in fluid communication with the first bladder;  
       (c) a third cell adjacent to and at least partially surrounding the second cell, the third cell comprising a third bladder, the third bladder in fluid communication with the second bladder;  
       (d) a first conduit connecting the first and second cells, the first conduit comprising a first flow restrictor; and  
       (e) a second conduit connecting the second and third cells, the second conduit comprising a second flow restrictor.  
     
     
       7. The carrier of  claim 6 , wherein the first and second flow restrictors comprise orifices. 
     
     
       8. The carrier of  claim 6  wherein the first and second restrictors each further comprise a diaphragm, the diaphragm adjustable for fluid flow therethrough. 
     
     
       9. A method for polishing a workpiece utilizing a chemical mechanical polishing carrier assembly, the system comprising: 
       (a) loading a workpiece into the carrier assembly, the carrier assembly having a plurality of pressure adjustable concentric bladders, the bladders in fluid communication with adjacent bladders via conduits;  
       (b) determining a removal rate profile for a plurality of concentric zones on a workpiece that correspond to the plurality of concentric bladders of the carrier;  
       (c) implementing the removal rate profile by controlling flow in the conduits and applying a desired pressure to the bladders;  
       (d) causing the workpiece to contact a polishing surface; and  
       (e) polishing the workpiece.  
     
     
       10. The method of  claim 9 , wherein the conduits comprise flow restrictors. 
     
     
       11. The method of  claim 10 , wherein the flow restrictors comprise orifices. 
     
     
       12. The method of  claim 10 , wherein the flow restrictors further comprise a diaphragm, the diaphragm adjustable for fluid flow therethrough. 
     
     
       13. The method of  claim 9  wherein the plurality of bladders comprises: 
       a) a first cell comprising a first flexible outer membrane;  
       b) a second cell comprising a second flexible outer membrane; and  
       c) a third cell comprising a third flexible outer membrane.  
     
     
       14. The method of  claim 13 , wherein the first cell further comprises a substantially cylindrical shape. 
     
     
       15. The method of  claim 13 , wherein the second and third cells further comprise annular concentric tubes, with a common center with the first cell.